Reciprocating plunger pump



P 10, 1968 H. P. WERTHEIMER 3,400,663

RECIPROCATING PLUNGER PUMi 2 Sheets-Sheet 2 Filed March 9, 1967 WITNESS:

ATTORNEY United States Patent 3,400,663 RECIPROCATING PLUNGER PUMP HarryP. Wert-heimer, Horseheads, N.Y., assignor to The Bendix Corporation, acorporation of Delaware Filed Mar. 9, 1967, Ser. No. 621,809 3 Claims.(Cl. 103-53) ABSTRACT OF THE DISCLOSURE A reciprocatingelectrom-agneticallydriven plunger pump comprised of interfittingU-shaped members forming a housing for pump elements. At least one ofthe U- shaped members is a substantial structural member and a goodmagnetic flux conductor. Inlet and outlet fittings are removable plugsor nut-like members retained in opp site legs of the structural U-shapedhousing member and retain between them pump sleeve and movable elementssuch as plunger and valves as a cartridge-like assembly. Electricalcomponents, for example coil, are retained concentrically piloted by oneof the fittings and retained laterally by a U-shaped member.

Summary of invention Prior electromagnetic plunger pumps are commonlyhoused in a cylindrical or canister-type container, as for example,described in commonly assigned US. Patent 2,994,792 in the name of L. C.Parker. Such canister pumps with solid state coil switching componentsare also known, as for example, described in co-pending U.S. applicationSer. No. 565,004, filed July 13, 1966.

The pump of the present invention consists of a basic reorganization ofpump structure to achieve a pump functionally equivalent, but at muchlower cost and more readily serviceable compared to known pump types.

The attainment of these and other objectives will become apparent onconsideration of the appended description :and drawings wherein:

FIGURE 1 is a cross-sectional view of a preferred embodiment of my pump;

FIGURE 2 is a plan view of the pump viewing the right side of the pumpas oriented in FIGURE 1; and

FIGURE 3 is a top view of the pump rotated 90 from the orientationillustrated in FIGURE 1.

Referring to the drawings, my pump is comprised of two interfittingU-shaped housing members and 12 which form the six sides of a volumetricspace for locating basic pump mechanical and electrical parts. Housingmember 12 has bent-over tabs 14, 16, 18 and 20 laterally forming aconnection with legs 22 and 24 of housing member 10.

Housing member 10 is fabricated from magnetic fluxconducting materialsuch as iron, steel or the like and the metal stock is relatively thick,providing a. rigid structural housing member. A pair of aligned holes,26 and 28, preferably threaded, are formed in legs 22 and 24respectively of housing member 10. An inlet fitting 30 in the form of ahexagonal plug or nut-like member is threaded into hole 28. An internalpassage formed in fitting 30 has varying diameter portions whichfunctionally comprise: inlet passage 32; inlet check valve seat 34;seating wall 36 for inlet check valve retainer; and inlet retaining bore38 of large diameter for receiving the plunger and sleeve cartridge. Inoutlet fitting 40, also in the form of a plug or hexagonal nut-likemember, is threaded into aligned opening 26 in leg 22. An internalpassage in fitting 40 forms an outlet passage 42 and an outlet retainingbore 44 of diameter equal and aligned to bore 38 for receiving plungerand sleeve cartridge. Outlet fitting 40 has a cylindrical extension 46projecting 'ice into the housing. Thin sleeve member 48 fits at oppositeends into bores 38 and 42 forming a sliding guide for piston or plunger50. Sleeve member 48 is fabricated from brass or other fluxnon-conducting material. Extension 46 of the outlet fitting extends intothe housing sufiiciently to provide significant axial overlap withpiston 50 for all pumping positions of the piston to insure adequatesurface for the transfer of flux from projection 46, through sleeve 48to plunger 50 (see arrows indicating flux transfer path in FIGURE 1).Projection 46 also provides a retaining bore internally for sleeve 48 asmentioned, and its external surface provides a locating surface for theannular plastic coil bobbin 52.

A through-passage 54 is formed in piston 50 and has a frusto-conicalsection 56 forming a seat for outlet check valve 58. Valve 58 isloose-fitting and guided by projecting spider 60 and prevented fromfalling loose by cross pin 62. A shoulder 64 is formed by throughbore 54and forms a retaining ledge for spring 66 which, on its lower end, abutsagainst inlet check valve retainer 68, holding it in position againstseating wall'36. Retainer 68 guides stem 70 of inlet check valve 72.Inlet check valve spring 74 is captured between retainer 68 and checkvalve 72. An electromagnetic power coil is disposed in bobbin 52. Anumber of different and known solid state circuits or interrupterarrangements may be used to obtain periodic energization of coil 80 andbasically do not form a part of the present invention. Copendingapplication Ser. No. 565,004 describes a solid state block oscillatorcircuit of the type that may be used which includes a signal detectioncoil which may also be wound on bobbin 52 as indicated by coil 82. Asillustrated in FIGURE 1, the legs 22 and 24 of housing member 10 extendto the right of the coil forming a space 84 for housing electricalswitching circuit components. Housing 12 has access openings 86 forcircuit leads which permit mounting exteriorly heat radiating componentssuch as the transistor 88, FIGURES 2 and 3. Plastic bobbin 52 has a tapportion 90 which extends through a slot, not shown, in leg 22.Power-terminal 92 is inserted through tab portion 90 which provideselectrical insulation providing a convenient connection toelectromagnetic coil and/or control circuit.

Functionally, the pump operates in a known manner. Energization of coil80 produces flux as indicated by the arrows which tends to shorten theworking air gap A by drawing picton 50 downwardly and simultaneouslycompressing spring 66. Downward motion opens check valve 58 and closescheck valve 72, causing fluid to flow to the top side of piston 50. Asthe oscillating or other control circuit interrupts current to coil 80allowing it to deenergize, spring 66 will release its stored energy,pushing piston 50 upwardly for a pumping stroke. Upward motion of piston50 also sucks a new fluid charge past inlet check valve 72.

The objective of low cost is achieved from the use of U-shapedinterfitting housing members providing common structure formerlyperformed by a number of separate and high tolerance pieces. TheU-shaped configuration is easily fabricated from low-cost stampings.Housing member 10 forms the backbone or major pump structural element.Additionally, it comprises the lateral pole pieces for coil 80, normallyprovided by separately fabricated pieces, as well as circumferentialflux path. Legs 22 and '24 are extended to provide space 84 within thepump housing for control circuit elements. Lastly, housing member 10 isthe mounting block for inlet and outlet fittings.

Housing member 12 completes the enclosure, provides a mounting surfacefor heat radiating electrical components and a pump mounting bracket.

Service is facilitated and it will be observed that simply unscrewinginlet fitting 30 and withdrawing, makes available all pump movingmechanical parts for service and/ or replacement. Removal of the secondfitting and separation of U-shaped housing segments makes available allelectrical elements.

Other variations of the pump may be made Without departing from thescope of the invention as defined in the appended claims.

I claim:

1. An electromagnetic plunger pump comprising:

first and second U-shaped housing members each having a pair ofinterfitting leg members forming opposite housing Walls and defining aninternal pump chamber;

an inlet fitting extending into an opening formed in one of said pair oflegs of said first housing member; an outlet fitting extending into anopening formed in the other of said pair of legs of said first housingmember and aligned with said inlet fitting;

a cylindrical sleeve member of non-magnetic material interposed betweensaid inlet and outlet fittings;

a fluid pumping piston member of magnetic material disposed in saidsleeve member and reciprocable therein; spring means bias said pistonmember in one direction; an electromagnetic coil member concentricallyarranged about said sleeve member and within the internal pump chamberformed by said U-shaped housing members;

said electromagnetic coil operative when energized to Y 4 v produce fluxmoving said piston against its spring bias; and one-way check valvemeans associated with said piston member permitting fluid to flowthrough said piston in one direction of movement and to block fluid flowthrough said piston in the other direction of movement.

2. An electromagnetic plunger pump as claimed in claim 1 wherein:

at least one of said first and second U-shaped housing members is madefrom magnetic flux conducting material forming a flux conducting polepiece circumferentially and on both lateral side of said electromagneticcoil member.

3. An electromagnetic plunger pump as claimed in claim 2 wherein:

References Cited UNITED STATES PATENTS 9/1931 Schtingut 103-53 8/1961Parker 310-18 ROBERT M. WALKER, Primary Examiner.

